imerinite

\\ˌiməˈrēˌnīt\ noun (-s)

Etymology: French imerinite, from Imerina, province of Madagascar, its locality + French -ite

: a monoclinic amphibole Na₂(Mg,Fe)₆Si₈O₂₂(O,OH)₂ that is related to richterite and occurs in colorless to blue acicular crystals : a basic silicate of sodium, iron, and magnesium